Lightweight building elements—an important category of such elements are lightweight building boards—comprise two outer, comparably thin building layers, for example of fiberboard or of a metal, and an interlining arranged between the building layer, for example a cardboard honeycomb structure. Lightweight building elements of this kind are mechanically very stable, may look pleasant and have a very low weight.
However, because the building layers are thin and the interlining is not suitable for anchoring a connector—such as a dowel—in it, it is difficult to attach an object to the lightweight building elements other then just by gluing it to the element's surface. Also, in some cases the mechanical stability between the building layers provided by the interlining is insufficient, and additional means for providing the stability would be desired. Similar requirements may arise if a mechanical stability between other objects is to be ensured, for example by mechanically connecting such objects.